Background: Proximal compensation to the distal movements is commonly observed in the affected upper extremity (UE) of patients with chronic stroke. However, the cortical origin of this compensation has not been well-understood. In this study, corticomuscular coherence (CMCoh) and electromyography (EMG) analysis were adopted to investigate the corticomuscular coordinating pattern of proximal UE compensatory activities when conducting distal UE movements in chronic stroke. Method: Fourteen chronic stroke subjects and 10 age-matched unimpaired controls conducted isometric finger extensions and flexions at 20 and 40% of maximal voluntary contractions. Electroencephalogram (EEG) data were recorded from the sensorimotor area and EMG signals were captured from extensor digitorum (ED), flexor digitorum (FD), triceps brachii (TRI), and biceps brachii (BIC) to investigate the CMCoh peak values in the Beta band. EMG parameters, i.e., the EMG activation level and co-contraction index (CI), were analyzed to evaluate the compensatory muscular patterns in the upper limb. Result: The peak CMCoh with statistical significance (P < 0.05) was found shifted from the ipsilesional side to the contralesional side in the proximal UE muscles, while to the central regions in the distal UE muscle in chronic strokes. Significant differences (P < 0.05) were observed in both peak ED and FD CMCohs during finger extensions between the two groups. The unimpaired controls exhibited significant intragroup differences between 20 and 40% levels in extensions for peak ED and FD CMCohs (P < 0.05). The stroke subjects showed significant differences in peak TRI and BIC CMCohs (P < 0.01). No significant inter- or intra-group difference was observed in peak CMCoh during finger flexions. EMG parameters showed higher EMG activation levels in TRI and BIC muscles (P < 0.05), and higher CI values in the muscle pairs involving TRI and BIC during all the extension and flexion tasks in the stroke group than those in the control group (P < 0.05). Conclusion: The post-stroke proximal muscular compensations from the elbow to the finger movements were cortically originated, with the center mainly located in the contralesional hemisphere.

中文翻译：

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卒中后手指运动过程中上肢的皮质肾小球连贯性（CMCoh）模式改变。

背景：在患中风的上肢（UE）的上肢（UE）中通常观察到远端运动的近端补偿。但是，这种补偿的皮层起源尚未得到很好的理解。在这项研究中，通过在慢性卒中中进行远侧UE运动时，通过近端UE代偿活动的皮层协调模式（CMCoh）和肌电图（EMG）分析来研究近端UE补偿活动的皮层协调模式。方法：十四名慢性中风受试者和十名年龄匹配的未受损对照者以最大自愿收缩的20％和40％进行了等距手指伸展和屈曲。从感觉运动区记录脑电图（EEG）数据，并从指趾伸肌（ED），指屈屈肌（FD），肱三头肌（TRI），和肱二头肌（BIC）来研究Beta波段的CMCoh峰值。分析肌电参数，即肌电激活水平和共收缩指数（CI），以评估上肢的代偿性肌肉模式。结果：在慢性卒中中，发现具有显着统计学意义的峰值CMCoh（P <0.05）从近端UE肌肉的同侧转移到对侧，而移动到远端UE肌肉的中央区域。在两组之间手指伸展过程中，ED和FD CMCohs峰均出现显着差异（P <0.05）。未受损的对照组在ED和FD CMCohs峰的延伸范围内表现出20％至40％水平的显着组内差异（P <0.05）。中风受试者的TRI和BIC CMCohs峰值显示出显着差异（P <0.01）。在手指屈曲过程中，CMCoh峰值未观察到明显的组间或组内差异。在卒中组的所有伸展和屈曲任务中，肌电参数显示出TRI和BIC肌肉的EMG激活水平更高（P <0.05），涉及TRI和BIC的肌肉对中的CI值高于对照组（P < 0.05）。结论：从肘部到手指运动的中风后近端肌肉补偿是皮质性起源的，其中心主要位于对侧半球。在中风组所有伸展和屈曲任务中，涉及TRI和BIC的肌肉对的CI值均高于对照组（P <0.05）。结论：从肘部到手指运动的中风后近端肌肉补偿是皮质性起源的，其中心主要位于对侧半球。在中风组所有伸展和屈曲任务中，涉及TRI和BIC的肌肉对的CI值均高于对照组（P <0.05）。结论：从肘部到手指运动的中风后近端肌肉补偿是皮质性起源的，其中心主要位于对侧半球。